diff --git a/intern/cycles/CMakeLists.txt b/intern/cycles/CMakeLists.txt
index 192b4e3c55d..2047a6fc98a 100644
--- a/intern/cycles/CMakeLists.txt
+++ b/intern/cycles/CMakeLists.txt
@@ -191,13 +191,6 @@ if(CXX_HAS_AVX2)
   add_definitions(-DWITH_KERNEL_AVX2)
 endif()
 
-# LLVM and OSL need to build without RTTI
-if(WIN32 AND MSVC)
-  set(RTTI_DISABLE_FLAGS "/GR- -DBOOST_NO_RTTI -DBOOST_NO_TYPEID")
-elseif(CMAKE_COMPILER_IS_GNUCC OR (CMAKE_C_COMPILER_ID MATCHES "Clang"))
-  set(RTTI_DISABLE_FLAGS "-fno-rtti -DBOOST_NO_RTTI -DBOOST_NO_TYPEID")
-endif()
-
 # Definitions and Includes
 
 add_definitions(
diff --git a/intern/cycles/kernel/osl/CMakeLists.txt b/intern/cycles/kernel/osl/CMakeLists.txt
index e0231796c90..653ed660dc7 100644
--- a/intern/cycles/kernel/osl/CMakeLists.txt
+++ b/intern/cycles/kernel/osl/CMakeLists.txt
@@ -36,9 +36,6 @@ set(LIB
   ${LLVM_LIBRARY}
 )
 
-# OSL and LLVM are built without RTTI
-string(APPEND CMAKE_CXX_FLAGS " ${RTTI_DISABLE_FLAGS}")
-
 if(APPLE)
   # Disable allocation warning on macOS prior to 10.14: the OSLRenderServices
   # contains member which is 64 bytes aligned (cache inside of OIIO's
diff --git a/intern/cycles/scene/CMakeLists.txt b/intern/cycles/scene/CMakeLists.txt
index 92b19303c94..ce4093cdf03 100644
--- a/intern/cycles/scene/CMakeLists.txt
+++ b/intern/cycles/scene/CMakeLists.txt
@@ -108,8 +108,6 @@ if(WITH_CYCLES_OSL)
   list(APPEND LIB
     cycles_kernel_osl
   )
-
-  set_property(SOURCE osl.cpp PROPERTY COMPILE_FLAGS ${RTTI_DISABLE_FLAGS})
 endif()
 
 if(WITH_OPENCOLORIO)